Shorted pickup vs open pickup, any effect on tone from the OTHER pickup?

[SharpCat]

In a normal two pickup circuit, when only one pickup is in use, the other is essentially shorted to ground by the turned-down volume pot. Contrast that with a circuit using a switch to select pickups. Often the unselected pickup is disconnected (at least on the hot lead) from the circuit completely.

I’m thinking about back-EMF being generated by the shorted coil causing an audible difference from the open coil configuration due to string interaction. Anyone have thoughts on this? Should switched pickups short the unused coils?

LP guitar players, can you hear a difference between turning down a volume to zero and flipping the toggle?

 

[Lo-E]

Pickup switching shouldn’t need to short coils. Those coils have been removed from the circuit.

Multi-pickup circuits that don’t use switches will almost always have a certain degree of interaction between the controls and the amount of interaction will vary widely based upon the combination of volume and tone controls that have been chosen and the topography of those controls. Back-EMF doesn’t really play into the equation.

Switching will reduce the interactions, especially if the switch removes from the circuit not only the pickup but also its associated volume and tone control.

Volume and tone pots affect the loading of the pickups and, depending upon how they’re wired, can affect the pickup that’s left on when the other is rolled off. Switching eliminates that sort of interaction so, in most cases, switching a pickup off does sound different than turning a pickup down. How obvious that difference is depends upon a lot of factors.